Method and device for adjusting height of manhole

ABSTRACT

A method and a device for safely and efficiently adjusting the height of a manhole freely allowing the addition and removal of a height adjusting member at any position. The method and device may be used for the manhole formed by installing a tubular shaped frame in the ground, installing the removable height adjustment members on the tubular shaped frame, and installing a cover receiving frame on the height adjusting members. In this method and device, a frame is disposed in the upper space of the manhole; the cover receiving frame is raised by the member installed on the frame; and the height adjusting members positioned under the cover receiving frame in that state are added or removed.

FIELD OF THE INVENTION

[0001] This invention relates to a method and a device for adjusting thelevel or height of a manhole.

DESCRIPTION OF THE PRIOR ART

[0002] A front surface of a manhole is supposed to be adjusted andleveled to become the same height as the road surface, thereby togetherforming a continuous, even surface.

[0003] However, as time goes by and after using the road for a longperiod of time, the road surface subsides leaving the manhole in itsinitial position, being exposed unnaturally.

[0004] If the road surface is raised, or the manhole subsides, the frontsurface of the manhole also subsides which may cause a traffic accident.

[0005] As a solution to the above-types of problems, adjustable heightmanholes have been developed.

[0006] As one example of the conventional art shown in FIG. 17, amanhole comprises a tubular shaped frame “a” positioned underground, anupwardly detachable height adjustment member “b” mounted on the tubularshaped frame “a”, and a cover receiving frame “c” mounted on the heightadjustment member “b”. The cover receiving frame “c” has plural boltholes formed therein.

[0007] An adjustment of the manhole height may be performed by driving aforce bolt “d” into each bolt hole in the cover receiving frame “c” topress the bottom surface of the bolt shaft against the top surface ofthe height adjustment member “b”.

[0008] Then, each force bolt “d” is further rotated to elevate the coverreceiving frame “c” with a reaction force generated therein. Afterelevating the cover receiving frame “c” to a certain degree, the heightadjustment member “b” is either removed if the road surface subsides oradded if the rode surface elevates, thereby adjusting the manhole heightto the same height as the road surface.

PROBLEMS TO BE RESOLVED BY THE INVENTION

[0009] A height adjustment process in the conventional manhole has thefollowing points to be improved:

[0010] 1. In the conventional manhole, the force bolt “d” is rotated toelevate the cover receiving frame “c” against the reaction force on theheight adjusting member “b”, and while the height adjustment member “b”is being removed or added, reaction force is being generated between thebottom surface of the shaft of the force bolt “d” and the top surface ofthe height adjustment member “b”.

[0011] Accordingly, the height adjustment member “B”, is positioned toface the bottom surface of the force bolt “d” and bears the forcecreated therebetween, as shown in FIG. 18, and is designed to be theun-removable height adjustment member “B”.

[0012] 2. Therefore, the height adjusting member “b” could be aring-shaped piece or a unit composed of individual, separate arc-shapedpieces. The conventional method includes a process of removing or addingarc-shaped height adjustment members “b” while the reaction force of theforce bolt “d” is being generated against some of the individual,separate, height adjustment members “b” that bear the reaction force.

[0013] The reaction force of the force bolt “d” is applied in sequenceagainst each un-removable height adjustment member “b” to change theheight thereof, ultimately changing the height of the entire manhole.

[0014] 3. A method for adjusting the height of the conventional manholeas described here is such that the arc-shaped height adjustment memberunderneath the force bolt “d” is always the un-removable adjustmentmember “B” which cannot be touched and therefore other height adjustmentmembers “b” need to be added or removed while the height of the forcebolt “d” is being changed.

[0015] 4. Because the un-removable height adjustment member “B” acts asan obstacle, height adjustment members “b” cannot be inserted ordeleted, and therefore other height adjustment members “b” need to beadded or deleted while the height of the force bolt “d” is beingchanged.

OBJECT OF THE INVENTION

[0016] This invention was made to improve the above describedconventional manhole. For that purpose, an object of this invention isto provide a safe, efficient and improved manhole which offers aflexible height adjusting mechanism with the ability to add or removeheight adjustment members at any height and a method for adjusting themanhole height with the same advantages.

[0017] This invention is a method for adjusting a manhole heightcomprising the steps of: positioning a tubular shaped frame underground;placing a removable height adjusting member on the tubular shaped frameand mounting a cover receiving frame thereon; positioning a base framein a space at an upper section of said manhole; lifting the coverreceiving frame by a drawing pole installed in the base frame; andremoving said height adjusting member placed under the cover receivingframe or adding said height adjusting member under the cover receivingframe.

[0018] This invention further is a device for adjusting a manhole heightcomprising: a tubular shaped frame positioned underground; a removableheight adjusting member placed on the tubular shaped frame; a coverreceiving frame mounted thereon; a base frame positioned in a space atan upper section of the manhole; and a drawing pole installed in thebase frame.

[0019] This invention further is a method for adjusting a manhole heightcomprising the steps of: positioning a tubular shaped frame underground;placing a removable height adjusting member on the tubular shaped frameand mounting a cover receiving frame thereon; positioning a base framein a space at an upper section of the manhole; arranging a pushingmember between the base frame and a road surface; connecting the baseframe and the cover receiving frame by the drawing pole; raising thecover receiving frame via the drawing pole by means of the pushingmember pushing the base frame up; forming a space underneath the coverreceiving frame; and removing the height adjusting member located underthe cover receiving frame or adding the height adjusting member underthe cover receiving frame.

[0020] This invention further is a device for adjusting a manhole heightcomprising a tubular shaped frame positioned underground; a removableheight adjusting member placed on the tubular shaped frame; a coverreceiving frame mounted thereon; a base frame positioned in a space atan upper section of the manhole; a pushing member arranged between thebase frame and a road surface; a drawing pole installed between the baseframe and cover receiving frame.

[0021] This invention further is a method for adjusting a manhole heightcomprising the steps of: positioning a tubular shaped frame underground;placing a removable height adjusting member on the tubular shaped frameand mounting a cover receiving frame thereon; positioning a support in aspace at an upper section of the manhole; setting an ascending base on asupporting base, said ascending base ascends relative to the supportingbase; connecting the ascending base and the cover receiving frame by aconnecting pole; lifting the cover receiving frame via the connectingpole as the ascending base ascends; forming a gap underneath the coverreceiving frame; and removing the height adjusting member placed underthe cover receiving frame or adding the height adjusting member underthe cover receiving frame.

[0022] This invention further is a method for adjusting a manhole heightcomprising the steps of: positioning a tubular shaped frame underground;placing a removable height adjusting member on the tubular shaped frame;and mounting a cover receiving frame thereon; positioning a supportingbase in a space at an upper section of the manhole; setting a pressfitting base on a supporting base, said press fitting base ascendsrelative to the supporting base; connecting the ascending base and thecover receiving frame by a connecting pole; descending the coverreceiving frame already ascended via the connecting pole as the pressfitting base descends; and closing a gap underneath the cover receivingframe.

[0023] This invention further is a device for adjusting a manhole heightcomprising a tubular shaped frame positioned underground; a removableheight adjusting member placed on the tubular shaped frame; a coverreceiving frame mounted thereon; a supporting base positioned in a spaceat an upper section of the manhole; a base, ascending and descendingrelative to the supporting base; an ascensor installed between thesupporting base and the ascending base; and a connecting member making aconnection between the ascending base and the cover receiving frame.

[0024] This invention further is a device for adjusting a manhole heightcomprising a tubular shaped frame positioned underground; a removableheight adjusting member placed on the tubular shaped frame; a coverreceiving frame mounted thereon; a supporting base positioned in a spaceat an upper section of the manhole; a press fitting base ascending anddescending relative to the supporting base; an ascensor installedbetween the supporting base and the press fitting base; and a connectingmember making a connection between the ascending base and the coverreceiving frame.

BRIEF DESCRIPTION OF THE DRAWINGS

[0025]FIG. 1 is a view explaining a manhole condition in a firstembodiment of the present invention where the road surface subsidesleaving the manhole to be exposed thereabove;

[0026]FIG. 2 is a view explaining a condition of a manhole in the firstembodiment of the present invention where the height adjustmentmechanism is installed;

[0027]FIG. 3 is a view explaining a condition of a manhole in the firstembodiment of the present invention where the cover receiving frame isbeing lifted;

[0028]FIG. 4 is a perspective view of a condition of a manhole in thefirst embodiment in the present invention where a cover receiving frameis being lifted;

[0029]FIG. 5 is a view explaining a condition of a manhole in the firstembodiment of the present invention where a new additional heightadjusting member is added;

[0030]FIG. 6 is a view explaining a height adjustment mechanism in asecond embodiment of the present invention;

[0031]FIG. 7 is a view explaining a condition of a manhole in the secondembodiment of the present invention in which a height adjustment memberis installed;

[0032]FIG. 8 is a view explaining a condition of a manhole of the secondembodiment in the present invention where a cover receiving frame isbeing lifted;

[0033]FIG. 9 is a perspective view of a condition of a manhole in thesecond embodiment of the present invention where a cover receiving frameis being lifted;

[0034]FIG. 10 is a view explaining a condition of a manhole in thesecond embodiment of the present invention where a new additional heightadjusting member is added;

[0035]FIG. 11 is a view explaining a height adjustment mechanism in athird embodiment of the present invention;

[0036]FIG. 12 is a view explaining a condition of a manhole in the thirdembodiment of the present invention where the height adjustmentmechanism is mounted in a space at an upper side of the manhole;

[0037]FIG. 13 is a view explaining a condition of a manhole in the thirdembodiment of the present invention where a cover receiving frame 3 isbeing lifted;

[0038]FIG. 14 is a perspective view of a condition of a manhole in thethird embodiment of the present invention where a cover receiving frame3 is being lifted;

[0039]FIG. 15 is a view explaining a condition of a manhole in the thirdembodiment of the present invention where a new additional heightadjusting member is added;

[0040]FIG. 16 is a view explaining a manhole structure having a pressfitting frame separately from a lifting frame;

[0041]FIG. 17 is a view explaining a conventional height adjustmentmechanism;

[0042]FIG. 18 is a view explaining positions with regard to theconventional non-removable height adjustment member and a force bolt.

FIRST EMBODIMENT OF THE INVENTION

[0043] A first embodiment of this invention with regard to a method anddevice for adjusting manhole height is explained with reference to theaccompanying drawings.

[0044] 1-1. Manhole Structure

[0045] A manhole in this invention may employ the identical structuresas disclosed in conventional manholes.

[0046] For installment of the conventional manholes, a tubular shapedframe 1 is positioned underground; a removable height adjusting member 2is placed on the tubular shaped frame 1; and a cover receiving frame 3is placed thereon. The shape of the frame 1 is not limited to be only acylindrical shape but may be any shape, such as a square shape forexample.

[0047] Each height adjusting member 2 is arc-shaped and the heightadjusting members 2 are able to be assembled to be combined together toform a tubular shaped unit and are capable of being disassembled inorder to each be separate height adjusting members 2.

[0048] The tubular frame 1, the height adjusting members 2, and thecover receiving frame 3 have plural through holes, and each through holeon the tubular frame 1, the height adjusting members, and the coverreceiving frame 3 are aligned to make one, vertical, slotted hole.

[0049] A bolt is inserted and screwed downward into each slotted hole tobe tightened therein so as to integrate the tubular shaped frame 1, theheight adjusting member 2 and the cover receiving frame 3.

[0050] If a peripheral covering tube 21 is installed to surround theheight adjusting members 2, then the inside of the tubular frame 1 willnot be exposed to surrounding soil when the height adjusting member 2 isremoved, thereby preventing any pebbles from falling into the tubularframe 1.

[0051] The peripheral covering tube 21 may be installed when a targetground surface is selected for placing the tubular shaped frame 1 is dugand cleared for positioning the manhole therein.

[0052] 1-2. Base Frame A4

[0053] This invention employs a base frame A4 positioned in a spaceabove the manhole.

[0054] Later described drawing poles A5 may accompany this base frameA4.

[0055] Here, for example, plural legs A41 are connected to the baseframe A4, which are designed such that the lower ends of the legs A41are extended to the periphery of the manhole.

[0056] Each leg A41 has its lower end placed on a base plate A42pressing the road surface around the periphery of the manhole and issupported thereon while receiving a reaction force of the base frame A4.Accordingly, when the cover receiving frame 3 is lifted, the base plateA42 prevents the surrounding pavement surface from lifting together withthe cover receiving frame.

[0057] The legs A41 of the base frame A4 may be a grate if they aredown-stretched and upwardly inclined toward the center of the manhole,and force bolts fitting in the base frame A4 are vertically screwed intobolt holes of the cover receiving frame 3.

[0058] Alternatively, the base frame A4 in a short tube-shape may bedesigned without the legs A41. As this short tube, an upper portion ofthe cone-like member is laterally cut to form a truncated cone baseframe, and drawing poles vertically extending from upper portions of thebase frame may be fit in the bolt holes formed on the cover receivingframe 3.

[0059] 1-3. Drawing Pole A5

[0060] There are various types of the drawing pole designed to lift thecover receiving frame 3.

[0061] For example, each drawing pole A5 comprises a nut mounted on thebase frame A4 and the force bolt screwed thereinto.

[0062] A lower end of the drawing pole A5 fits into the cover receivingframe 3, and the nut on the base frame A4 is rotated to elevate thecover receiving frame 3 at the lower end portion of the force bolt.

[0063] Alternatively, the drawing pole A5 may comprise a jack and alifting member mounted on the base frame A4.

[0064] The lifting member may be a steel pole or a steel wire. The jackmay be such as a publicly available screw jack and/or center hole jack.

[0065] Each lower end of the pulling member is fixed in the coverreceiving frame 3, and the jack is operated to lift the pulling memberup raising the cover receiving frame 3 positioned at the lower endportion of the pulling member.

[0066] Alternatively, various conventional lifting means may be used tolift the cover receiving frame 3, such as a lifting motor with a motorused to wind the steel wire, a pantograph mechanism, or an elevator.

[0067] 1-4. Installment of the Drawing Pole A5

[0068] A method for adjusting the height of the cover receiving frame 3when the cover receiving frame 3 is exposed and juts out above the roadsurface, due to ground subsidence, will be explained next.

[0069] To begin with, the manhole cover is removed and the base frame A4is positioned in the space at the upper portion of the manhole withoutthe cover (FIG. 2).

[0070] The force bolts that fit through the bolt holes of the tubularshaped frame 1, the height adjusting members 2, and the cover receivingframe 3 at the manhole side, are removed.

[0071] The ends of the drawing poles A5, installed in the base frame A4,fit in the cover receiving frame 3.

[0072] If the drawing poles A5 are bolt-like members, i.e., havingthreaded sections, the end portions of the threaded section may bescrewed into the opened holes on the cover receiving frame 3 afterremoving the force bolts which were previously extended through thetubular shaped frame 1, the height adjusting members 2 and the coverreceiving frame 3.

[0073] Alternatively, if separate bolt holes for lifting are placed inthe cover receiving frame 3, the lower ends of the bolts may fittherein.

[0074] If the drawing poles A5 are steel poles or steel wires, the coverreceiving frame 3 may be an L-shape in the cross-section and a base lineof the L-shape extends toward the manhole center. The surface of thebase line is designed to have plural holes through which the ends of thedrawing poles A5 are placed and are to be fixed therein.

[0075] 1-5 Lifting by the Drawing Pole A5 (FIGS. 3 and 4).

[0076] The nuts over the drawing poles A5 may be rotated or the liftingjack may be activated to raise the drawing poles A5. If the drawingpoles A5 are long bolts, then, the nuts fitting over the bolts, whilerestricting the rotation of the bolts and being mounted on the baseframe A4, may be rotated to draw the bolts without rotating the same.The same explanation may be made to the case when the bolts descend orare lowered.

[0077] As such, the lower ends of the drawing poles A5, installed in thecover receiving frame 3, ascend with a reaction force against the baseframe A4. The cover receiving frame 3 also ascends together as thedrawing poles A5 are drawn.

[0078] At that time, unlike the conventional manhole arts, the coverreceiving frame 3 does not receive the reaction force against the heightadjustment members 2 below, and therefore the cover receiving frame 3and the height adjusting members 2 are completely separated.

[0079] 1-6 Height Adjustment (FIG. 5).

[0080] Because the cover receiving frame 3 is completely separated fromthe height adjusting members 2 below, new additional height adjustingmembers 2N may be added at any location. Additionally, the heightadjusting members 2 may be removed at any location.

[0081] Accordingly, this manhole does not require the height change ofthe force bolts, thereby providing a quick and safe process of adding orremoving the level height adjustment members 2.

[0082] 1-7 Pressing the Ground

[0083] When the base frame A4 is properly positioned, lower ends ofplural legs A41 of the base frame A4 are placed on the ground around theperiphery of the manhole. If the base frame A4 is a short tube then abottom surface of the short tube lands on the periphery of the manhole.

[0084] The cover receiving frame 3 is lifted while the bottom surface,placed on the periphery of the manhole, generates the reaction forceagainst the base frame A4. The legs A41 and the bottom surface of thebase frame A4 press against the ground around the manhole preventing thepavement therearound from raising or from being pulled up.

SECOND EMBODIMENT OF THIS INVENTION

[0085] A second embodiment regarding a method for adjusting the heightof the manhole in this invention and the adjusting device is explainedhere with reference to FIGS. 6-10.

[0086] 2-1. Manhole Structure

[0087] The method and the device described in this embodiment areapplicable and employable to the manhole of an identical structure ofthe previous embodiment using the height adjusting members.

[0088] 2-2. Base frame B4

[0089] This invention employs a base frame B4 positioned in a spaceabove the manhole.

[0090] The base frame B4 is a frame capable of having drawing poles B5installed thereon and may be formed in various shapes, such as acircular shape or a rectangular shape, according to the shape of themanhole.

[0091] 2-3. Drawing Pole

[0092] Plural pushing members B41 are sandwiched between the base frameB4 and the road surface 22 having a reaction plate B42 therebetween.

[0093] For example, vertically strokable jacks may be used as thepushing members B41 for the base frame B4. The jacks are not limited tohydraulic/oil jacks but may be any of the various conventional jackssuch as screw jacks, pneumatic/air jacks, or pantograph jacks.

[0094] Plural jacks are connected with one pump via connecting pipes.For example, one manual pump supplies air pressure or hydraulic pressureto the pushing member B41 to either ascend or descend the entire baseframe B4 evenly.

[0095] The pushing members that are comprised of nuts mounted on thebase frame B4 and vertical bolts may be used to rotate the bolt stem toascend or descend the base frame B4.

[0096] Alternatively, various mechanisms generally known to the public,e.g., a mechanism designed to convert rotation into either an ascendingor descending movement, such as a combination of a rack and pinion, maybe employed here.

[0097] 2-4. Reaction Plate

[0098] Reaction plates B42 may be placed underneath the lower ends ofthe pushing members B41 ascending the base frame B4. The reaction platesB42 encircle the ground around the periphery of the manhole.

[0099] When the base frame B4 ascends, the reaction force of the pushingmembers B41 is transmitted to the road surface 22 around the peripheryof the manhole via the reaction plates B42, thereby preventing theground therearound from arising while lifting the cover receiving frame3. Accordingly, when the cover receiving frame 3 is lifted, the reactionplate B42 prevents the surrounding pavement surface from rising uptogether with the cover receiving frame 3.

[0100] 2-5. Drawing Pole B5

[0101] Various types of drawing poles B5 may be used to lift or raisethe cover receiving frame 3.

[0102] For example, each drawing pole B5 comprises a nut mounted on thebase frame B4 and the force bolt screwed thereinto.

[0103] Alternatively, publicly available steel poles or steel wires maybe employed as the drawing poles B5.

[0104] If each lower end of the drawing poles B5 is fixed in the coverreceiving frame 3 while each upper end thereof is fixed in the baseframe B4 to ascend the base frame B4, the cover receiving frame 3, inwhich the lower ends of the drawing poles B5 are installed, may belifted as a result.

[0105] 2-6. Installment of the Drawing Pole B5

[0106] If the road surface subsides, the cover and the cover receivingframe 3 of the manhole will be exposed above the road surface. A methodfor adjusting the height of the cover receiving frame 3 when the coverand the cover receiving frame 3 are exposed will be explained next.

[0107] To begin with, the manhole cover is removed and the base frame B4is positioned in a space at the upper portion of the manhole without thecover. FIG. 7

[0108] The force bolts, fitting through the bolt holes of the tubularshaped frame 1, the height adjusting members 2, and the cover receivingframe 3 at the manhole side, are removed.

[0109] The ends of the drawing poles B5, installed in the base frame B4,fit in the cover receiving frame 3.

[0110] If the drawing poles B5 are bolt-like members, i.e., havingthreaded sections, the end portions of the threaded section may bescrewed into the opened holes in the cover receiving frame 3, afterremoving the force bolts which were previously extended through thetubular frame 1, the height adjusting members 2 and the cover receivingframe 3.

[0111] Alternatively, if separate bolt holes for lifting are placed inthe cover receiving frame 3, the lower ends of the bolts may fittherein.

[0112] If the drawing poles B5 are steel poles or steel wires, the coverreceiving frame 3 may be L-shaped in cross-section and a base line ofthe L-shape extends toward the manhole center. A surface of the baseline is designed to have plural holes through which the ends of thedrawing poles B5 are placed therethrough and are to be fixed therein.

[0113] 2-7. Pushing of the Base Frame (FIGS. 8 and 9)

[0114] The pushing members B41 push the base frame B4 up.

[0115] The base frame B4 is being pushed upward and the drawing polesB5, whose lower ends are installed in the cover receiving frame 3 causesthe cover receiving frame 3 to ascend or to be pulled upward as thedrawing poles B5 are drawn upward.

[0116] Unlike the conventional arts, the cover receiving frame 3 doesnot receive the reaction force against the height adjustment members 2below. The height adjusting members B do not exist between the coverreceiving frame 3 and the height adjusting members 2, and therefore thecover receiving frame 3 and the height adjusting members 2 arecompletely separate.

[0117] 2-8. Addition of Height Adjusting Members (FIG. 10)

[0118] Because the cover receiving frame 3 is completely separated fromthe height adjusting members 2 below, new additional height adjustmentmembers 2N may be added at any location.

[0119] Conversely, the height adjusting members 2 may be removed at anylocation.

[0120] Accordingly, this manhole does not require the height change ofthe force bolts as is required in the conventional manholes, therebyproviding a quick and safe process for adding or removing the heightadjusting members 2.

[0121] 2-9. Pressing the Ground

[0122] When the base frame B4 is properly positioned around the manholethe lower ends of plural legs B41 of the base frame B4 are placed on theground around the periphery of the manhole.

[0123] The cover receiving frame 3 may be lifted while the bottomsurface, placed on the periphery of the manhole, generates a reactionforce against the base frame B4. Then, the bottom surface of the legsB41 and the reaction plate B42 press against the ground around themanhole thus preventing the pavement, such as an asphalt surfacetherearound, from raising.

THIRD EMBODIMENT OF THIS INVENTION

[0124] A third embodiment of this invention, a method and device foradjusting the height of a manhole, is explained with reference to theaccompanying drawings.

[0125] 3-1. Manhole Structure

[0126] The method and the device described in this embodiment areapplicable and employable to a manhole having the identical structure ofthe previous embodiments using the height adjusting members.

[0127] 3-2. Base frame C4

[0128] A base frame C4 is a joist-like supporting member laterallypositioned in an upper space of a manhole that receives a reaction forcedue to lifting and lowering of a cover receiving frame 3.

[0129] Surrounding portions of the base frame C4 are supported by pluralsupporting posts C41 in order to position the base frame C4 in the upperspace of the manhole.

[0130] The plural supporting posts C41 are equally arranged at thesurrounding portions of the base frame C4 along the manhole shape. Eachsupporting post C41 has a base plate underneath.

[0131] In consideration of the plural supporting posts C41 equallyarranged at the surrounding portions of the base frame C4 along themanhole shape, one larger tube shaped member may be substituted for theplural supporting posts C41 so as to eliminate the need for independentsupporting posts C41.

[0132] The base frame C4 has an ascensor C51 or plural ascensors C51equally positioned at or around a central region thereof.

[0133] An example as shown in FIG. 11 shows the base frame C4 with oneascensor C51 at the center thereof and three beams vertically extendingat radial positions thereof. However, the base frame C4 may be adisc-shape, a rectangular-shape, or any other possible shapes.

[0134] 3-3. Ascending Base C5

[0135] An ascending base C5 is positioned in an upper space above thesupporting base C4 or a lower space below the supporting base C4.

[0136] This ascending base C5 ascends or descends its position relativeto the fixed supporting base C4.

[0137] As shown in the FIG. 5 example, although the base frame C4 maycomprise one ascensor C51 at the center thereof and three beamsvertically extending at radial positions thereof, base frame C4 may be adisc-shape, a rectangular-shape, or any other possible shapes.

[0138] The ascending base C5 has the later described connecting polesC52.

[0139] 3-4. Ascensor C5

[0140] One or plural ascensors C51 may be installed between thesupporting base C4 and the ascending base C5

[0141] For example, vertically strokable jacks may be used as theascensor C51. The jacks are not limited to hydraulic/oil jacks but maybe any of the various conventional jacks such as manual screw jacks,pneumatic/air jacks, or pantograph jacks.

[0142] Alternatively, nuts may be mounted on the supporting base C4 andbolts may be used as the ascensors C51, so that the ascending base C5may ascend or descend by rotating the bolt via a ratchet engagement.

[0143] Alternatively, various mechanisms generally known to the public,e.g., a mechanism designed to convert rotation into either an ascendingor descending movement, such as a combination of a rack and pinion, maybe employed here.

[0144] Plural jacks are connected with one pump via connecting pipes,and, for example, one manual pump supplies air pressure or hydraulicpressure to the ascensor C51 so as to push base C5 to either ascend ordescend the entire base frame B4 evenly.

[0145] The ascensor C51 may be comprised of only one jack, whicheliminates the need of adjusting the speed among plural jacks.

[0146] The ascensor C51 may be comprised of plural jacks, which providesmore stable ascending and descending of base C5 because of the weightdispersion.

[0147] 3-4. Bottom Plate

[0148] The supporting post C41 supporting the supporting base C4 has abase plate underneath. The bottom plate is designed to be circularlypositioned on the ground around the periphery of the manhole.

[0149] When the base C5 ascends the reaction force of the ascensor C51is transmitted to the road surface around the periphery of the manholevia the bottom plate, thereby preventing the ground therearound fromarising by ascending the cover receiving frame 3.

[0150] Accordingly, when a cover receiving frame 3 is lifted, the bottomplate prevents the surrounding pavement surface from raising togetherwith the cover receiving frame 3.

[0151] 3-6. Connecting Pole C52

[0152] Connecting poles C52 are vertically extended from the base C5.

[0153] Various conventional structures may be employed in the connectingpoles C52, but each connecting pole C52 has a lower end mounted to thecover receiving frame 3, which lifts the cover receiving frame 3 bymeans of ascending the base C5.

[0154] For example, the connecting pole C52 may comprise a long steelpole with a threaded section at an end thereof and a nut mounted on theascending base C5 making a screw engagement with the threaded section.

[0155] Alternatively, publicly available steel poles or steel wires maybe employed as the connecting pole C52.

[0156] If each lower end of the connecting poles C52 is fixed in thecover receiving frame 3 while each upper end thereof is fixed in thesupporting base C4 to ascend the base C5, then the cover receiving frame3, in which the lower ends of the connecting poles C52 are installed,may ascend as a result of the connecting pole movement.

[0157] The cover receiving frame 3 firmly attaches to the surroundingpavement, and therefore, an initial step of loosening the manhole rimrequires large tension force. At that time, if the connecting poles C52and the ascending base C5 are tied together by bolts C53, the initialmanhole rim may be loosened by rotating the bolts C53.

[0158] 3-7. Press Fitting Base C6

[0159] After the cover receiving frame 3 is lifted it needs to belowered to close the gap thereunder.

[0160] This descending process may be accomplished by descending thebase C5. However, a press fitting base C6 may be provided in addition tothe base C5.

[0161] Just like the base C5, the fitting base C6 is positioned in anupper space above the supporting base C4 or a lower space below thesupporting base C4.

[0162] This fitting base C6 also ascends or descends its positionrelative to the fixed supporting base C4. Similar to the supporting baseC4, although the fitting base C6 may comprise three beams verticallyextending at radial positions thereof, the supporting base C4 may be adisc-shape, a rectangular-shape, or any other possible shapes.

[0163] Connecting poles C52 are removably installed in the press fittingbase C6 via nuts.

[0164] When the press fitting base C6 is positioned at an opposite sideof the base C5 relative to the supporting base C4 as shown in anexample, if a hydraulic/oil pressure jack is used as the ascensor C51,ascending of the base C5 and descending of the press fitting base C6 maybe facilitated by means of swinging the hydraulic/oil pressure jack inboth directions.

[0165] 3-8. Step of Fixing Connecting Pole C52 and Cover receiving Frame3

[0166] A method for adjusting the height of the cover receiving frame 3will be explained next.

[0167] If the road surface subsides, the cover and the cover receivingframe 3 of the manhole will be exposed above the road surface.

[0168] To begin with, the manhole cover is removed and the supportingbase C4 and the base C5 are positioned in a space at an upper portion ofthe manhole without the cover (FIG. 12).

[0169] The force bolts, fitting through the bolt holes of the tubularshaped frame 1, the height adjusting members 2, and the cover receivingframe 3 at the manhole side, are removed.

[0170] The ends of the connecting poles C52 installed in the base C5 fitin the cover receiving frame 3.

[0171] If the connecting poles C52 are bolt-like members, i.e., havingthreaded sections, then the end portions of the threaded sections may bescrewed into holes opened on the cover receiving frame 3 after removingthe force bolts which were previously extending through the tubularframe 1, the height adjusting members 2, and the cover receiving frame3.

[0172] Alternatively, if separate bolt holes for lifting are opened onthe cover receiving frame 3, the lower ends of the bolts may fittherein.

[0173] If the connecting poles C52 are steel poles or steel wires, thecover receiving frame 3 may be an L-shape in cross-section and a baseline of the L-shape extends toward the manhole center. The surface ofthe base line is designed to have plural holes through which the ends ofthe connecting poles C52 are placed and are to be fixed therein.

[0174] 3-9 Step of Ascending the Base Frame (FIGS. 13 and 14)

[0175] The ascensor C51 lifts the base C5.

[0176] As the base C5 is lifted, the connecting poles C51, which havethe lower ends installed in the cover receiving frame 3, lifts the coverreceiving frame 3. The cover receiving frame 3 also ascends together asthe connecting poles C52 are drawn upward.

[0177] At that time, unlike the conventional arts, because the coverreceiving frame 3 does not receive the reaction force against the heightadjustment members 2 below, the height adjusting members B, which cannotbe removed, do not exist between the cover receiving frame 3 and theheight adjusting members 2, and therefore the cover receiving frame 3and the height adjusting members 2 are completely separated.

[0178] 3-10 Addition of Height Adjusting Members (FIG. 15)

[0179] Because the cover receiving frame 3 is completely separated fromthe height adjusting members 2 below, new additional height adjustingmembers 2N may be added at any location.

[0180] In other words, the height adjusting members 2 may be removed atany location.

[0181] Accordingly, this manhole does not require the height change ofthe force bolts as is required in the conventional manholes, therebyproviding a quick and safe process of adding or removing the heightadjusting members 2.

[0182] 3-11 Pressing the Ground

[0183] The reaction force of the lifting operation of base C5 istransmitted to the ground via the supporting posts C41 located aroundthe periphery of the manhole.

[0184] For that purpose, the bottom plates press the ground around themanhole, thereby preventing the pavement, such as an asphalt surfacetherearound, from raising.

[0185] 3-12 Step of Descending the Cover Receiving Frame 3

[0186] The cover receiving frame 3, once ascended, needs to be descendedto be in an appropriate position.

[0187] For that purpose the base C5 needs to be descended or the pressfitting base C6 needs to be descended.

[0188] Then, the connecting poles C52 descend and the cover receivingframe 3 connected at the lower ends of the connecting poles C52 alsodescends to be in an appropriate position.

[0189] At that time, if the reaction force to descend is insufficient,one end of a reaction force arm C61 is connected to the supporting postsC41. The other end of the reaction force arm C61 engages with astationary portion within the manhole, such as with the tubular shapedframe.

[0190] The reaction force of the press fitting is transmitted to frameslike the manhole via the press fitting base C6, the ascensor C51, thesupporting base C4, and the reaction force arm C61, thereby facilitatingthe press fitting process

[0191] The same could be said when the press fitting base C6 is used inaddition to the base C5 or a member with the combined functions of thebase C5 and the press fitting base C6 is used.

ADVANTAGES OF THIS INVENTION

[0192] The method and device for adjusting the manhole height in thisinvention is designed to lift the cover receiving frame instead of onlypushing the cover receiving frame, as is shown in the conventional arts.Accordingly, this invention has the following advantages.

[0193] 1. The cover receiving frame and the height adjusting members 2,at its lower side, are completely separated. Therefore, an additionalheight adjusting member 2 may be placed in any location and also theheight adjusting member 2 may be removed at any location, whichincreases the efficiency of the entire operation.

[0194] 2. Because of the above described efficiency, this inventionprovides an effective adjusting method and a device, especially for amanhole located in a busy road.

[0195] 3. The reaction force of the lifting operation of the coverreceiving fame 3 is transmitted to the ground around the periphery ofthe manhole via the legs of the base frame and the bottom surfaces.Accordingly, the larger the resistance of lifting the cover receivingframe 3 is the more effective the prevention of damages to the groundand the pavement is because the ground around the manhole is firmlysecured by the base frame and the bottom surfaces.

[0196] 4. In the method and the device of embodiment 3, the coverreceiving frame 3, once lifted by the ascending base or the pressfitting base separate from the ascending base, may be press-fit, therebycompleting the adjustment quickly.

[0197] It is readily apparent that the above-described invention isadvantageous for use in wide commercial utility. It may be understoodthat the specific form of the invention hereinabove is intended to berepresentative only, and certain modifications within the scope of theseteachings will be apparent to those skilled in the art without departingfrom the spirit and scope of the invention.

[0198] Accordingly, reference should be made to the following claims indetermining the full scope of the invention.

What we claim is:
 1. A method for adjusting a manhole height comprisingthe steps of: positioning a tubular shaped frame underground; placing aremovable height adjusting member on the tubular shaped frame andmounting a cover receiving frame thereon; positioning a base frame in aspace at an upper section of said manhole; lifting the cover receivingframe by a drawing pole installed in the base frame; and removing saidheight adjusting member placed under the cover receiving frame or addingsaid height adjusting member under the cover receiving frame.
 2. Adevice for adjusting a manhole height comprising: a tubular shaped framepositioned underground; a removable height adjusting member placed onthe tubular shaped frame; a cover receiving frame mounted thereon; abase frame positioned in a space at an upper section of the manhole; anda drawing pole installed in the base frame.
 3. A method for adjusting amanhole height comprising the steps of: positioning a tubular shapedframe underground; placing a removable height adjusting member on thetubular shaped frame and mounting a cover receiving frame thereon;positioning a base frame in a space at an upper section of the manhole;arranging a pushing member between the base frame and a road surface;connecting the base frame and the cover receiving frame by the drawingpole; ascending the cover receiving frame via the drawing pole by meansof the pushing member pushing the base frame up; forming a spaceunderneath the cover receiving frame; and removing the height adjustingmember located under the cover receiving frame or adding the heightadjusting member under the cover receiving frame.
 4. A device foradjusting a manhole height comprising a tubular shaped frame positionedunderground; a removable height adjusting member placed on the tubularshaped frame; a cover receiving frame mounted thereon; a base framepositioned in a space at an upper section of the manhole; a pushingmember arranged between the base frame and a road surface; a drawingpole installed between the base frame and cover receiving frame.
 5. Amethod for adjusting a manhole height comprising the steps of:positioning a tubular shaped frame underground; placing a removableheight adjusting member on the tubular shaped frame and mounting a coverreceiving frame thereon; positioning a support in a space at an uppersection of the manhole; setting an ascending base on a supporting base,said ascending base ascends relative to the supporting base; connectingthe ascending base and the cover receiving frame by a connecting pole;lifting the cover receiving frame via the connecting pole as theascending base ascends; forming a gap underneath the cover receivingframe; and removing the height adjusting member placed under the coverreceiving frame or adding the height adjusting member under the coverreceiving frame.
 6. A method for adjusting a manhole height comprisingthe steps of: positioning a tubular shaped frame underground; placing aremovable height adjusting member on the tubular shaped frame; andmounting a cover receiving frame thereon; positioning a supporting basein a space at an upper section of the manhole; setting a press fittingbase on a supporting base, said press fitting base ascends relative tothe supporting base; connecting the ascending base and the coverreceiving frame by a connecting pole; descending the cover receivingframe already ascended via the connecting pole as the press fitting basedescends; and closing a gap underneath the cover receiving frame.
 7. Adevice for adjusting a manhole height comprising a tubular shaped framepositioned underground; a removable height adjusting member placed onthe tubular shaped frame; a cover receiving frame mounted thereon; asupporting base positioned in a space at an upper section of themanhole; a base, ascending and descending relative to the supportingbase; an ascensor installed between the supporting base and theascending base; and a connecting member making a connection between theascending base and the cover receiving frame.
 8. A device for adjustinga manhole height comprising a tubular shaped frame positionedunderground; a removable height adjusting member placed on the tubularshaped frame; a cover receiving frame mounted thereon; a supporting basepositioned in a space at an upper section of the manhole; a pressfitting base ascending and descending relative to the supporting base;an ascensor installed between the supporting base and the press fittingbase; and a connecting member making a connection between the ascendingbase and the cover receiving frame.